Crying Wolf?
The Challenge of False Alarms in Flood Early Warning Systems
Following the terrible flooding disaster on the Guadalupe River in Texas, the New York Times recently called attention to underinvestment in early warning systems ("Around the World, Early Warning Systems Struggle to Prevent Flash Flooding Disasters," July 14, 2025). The article points to the deep challenge of predicting flash floods and mentions the so-called “cry wolf” problem—the idea that false alarms can lull communities into inaction.
There is a lot of valuable research on early warning systems for flooding and other natural disasters. Much of it emphasizes the complex chain that leads from data to modeling to prediction to warning to response (see, for example, Fernández-Nóvoa, González-Cao and García-Feal, 2024*). The bottomline: it ain’t easy to avoid false alarms.
I looked around for research on this cry wolf issue and found an interesting article by Sawada, Kanai and Kotani (2022)** that summarizes past research on this phenomenon. They find that past research generally supports the importance of "cry wolf" effects, though several studies find neglible or insignificant effects.
Recent research by Kotani, Ogawa and Matshushima (2025)*** using data from the 2018 floods in Japan finds support for the economic and social consequences of a higher number of false alarms. They find that a greater number of false alarms is related to a higher number of fatalities, injuries and economic losses.
The conclusion I draw from this research is that high quality early warning systems are essential for saving lives, but we also need to be aware of how early warning systems can interact negatively with public perceptions of risk.
Chris Ansell
REFERENCES
*Fernández-Nóvoa, D., González-Cao, J., & García-Feal, O. (2024). Enhancing flood risk management: a comprehensive review on flood early warning systems with emphasis on numerical modeling. Water, 16(10), 1408.
**Sawada, Y., Kanai, R., and Kotani, H.: Impact of cry wolf effects on social preparedness and the efficiency of flood early warning systems, Hydrol. Earth Syst. Sci., 26, 4265–4278, https://doi.org/10.5194/hess-26-4265-2022, 2022).
***Kotani, H., Ogawa, W., & Matsushima, K. (2025). Does the performance of a flood early warning system affect casualties and economic losses? Empirical analysis using open data from the 2018 Japan Floods. Journal of the Meteorological Society of Japan. Ser. II, 103(4), 481-496.